pandas.Series.to_period — pandas 2.2.3 documentation (original) (raw)

Series.to_period(freq=None, copy=None)[source]#

Convert Series from DatetimeIndex to PeriodIndex.

Parameters:

freqstr, default None

Frequency associated with the PeriodIndex.

copybool, default True

Whether or not to return a copy.

Note

The copy keyword will change behavior in pandas 3.0.Copy-on-Writewill be enabled by default, which means that all methods with acopy keyword will use a lazy copy mechanism to defer the copy and ignore the copy keyword. The copy keyword will be removed in a future version of pandas.

You can already get the future behavior and improvements through enabling copy on write pd.options.mode.copy_on_write = True

Returns:

Series

Series with index converted to PeriodIndex.

Examples

idx = pd.DatetimeIndex(['2023', '2024', '2025']) s = pd.Series([1, 2, 3], index=idx) s = s.to_period() s 2023 1 2024 2 2025 3 Freq: Y-DEC, dtype: int64

Viewing the index

s.index PeriodIndex(['2023', '2024', '2025'], dtype='period[Y-DEC]')